An apparatus is disclosed in Japanese patent Unexamined Publication Toku-Kai-Hei (JP(A)) 8-19940, where, after axially-thin works are through-fed to a centerless grinder and processed with grinding therein, the works are aligned axially along the horizontal direction on a guide plate, and pushed out of the discharging end (or front end) of the guide plate by means of a thrust force provided during the grinding, to fall onto a discharge chute disposed below, by means of their own weight. The works are then conveyed by means of the discharge chute into a laser measuring device, where the works are passed through the laser measuring device in a radial direction to measure the outer diameter of the works for quickly feeding back the measuring results to the centerless grinder. In the method and apparatus for discharging works from a centerless grinder, as disclosed in the Japanese patent Unexamined Publication, the works processed with grinding are aligned axially in a horizontal direction, on a guide plate disposed on the discharging side of the centerless grinder, and by means of a thrust force provided during the grinding is caused to fall radially in the vertical direction, piece by piece, out of the discharging end (or front end) of the guide plate utilizing air and their own weight, to be collected onto a discharge chute disposed below.
The disclosed apparatus has the disadvantage in that, while the axially-thin works ground and aligned on the guide plate disposed on the discharging side of the centerless grinder, and pushed out of the front end of the guide plate by means of a thrust force provided during the grinding, neighboring works tend to be engaged with each other by means of grinding burrs, whereby, if the grinding speed is increased, it becomes difficult to cause the works to fall, piece by piece, radially in the vertical direction, by means of flowing air and their own weight, as the works are coming out of the front end of the guide plate, with a high probability that two neighboring works fall together. When two works fall together, the discharge chute is clogged with the works resulting in the transportation of the works to the measuring device being stopped. Then the works in the grinding process is caused to undergo processing for an excessive period of time, and, in turn, become defective. Once this condition occurs, the centerless grinder must be temporarily stopped for discharging all of the unfinished works, and then restarted, which causes loss due to deterioration in yield and availability.
While a method is being implemented including the steps of causing works to fall vertically in the radial direction of the works by pressing downward on the works being pushed out of the front side of the guide plate by means of a roller energized (given force) vertically downward with a spring, instead of flowing air, such steps have not succeeded in solving the problem whereby two neighboring works pushed out of the guide plate tend to fall together, when the grinding speed is increased.
The present invention has been made to solve this problem. Accordingly, an object of the present invention is to provide a method and apparatus for discharging works from a centerless grinder where the works, ground and being pushed axially along the horizontal direction out of a guide plate disposed on the discharging side of the centerless grinder are caused to fall, piece by piece, radially in the vertical direction, even when the grinding speed is increased.